// Muduo - A reactor-based C++ network library for Linux
// Copyright (c) 2010, Shuo Chen.  All rights reserved.
// http://code.google.com/p/muduo/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
//   * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//   * Neither the name of Shuo Chen nor the names of other contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


#ifndef CLUSNET_BASE_TIMESTAMP_H
#define CLUSNET_BASE_TIMESTAMP_H

#include <algorithm>
#include <string>

namespace clusnet
{
namespace base
{

class Timestamp final 
{
    public:
        Timestamp(const Timestamp&) = default;
        Timestamp(Timestamp&&) = default;
        Timestamp& operator= (const Timestamp&) = default;
        Timestamp& operator= (Timestamp&&)  = default;
        ~Timestamp() = default;
        Timestamp()
            : microSecondsSinceEpoch_(0)
        {
        }

        explicit Timestamp(int64_t microSecondsSinceEpochArg)
            : microSecondsSinceEpoch_(microSecondsSinceEpochArg)
        {
        }

    public:
        void swap(Timestamp& that)
        {
            std::swap(microSecondsSinceEpoch_, that.microSecondsSinceEpoch_);
        }

        std::string toString() const;
        std::string toFormattedString(bool showMicroseconds = true) const;

        static size_t toFormattedString(char (&buf)[64], time_t seconds);

        bool valid() const
        {
            return microSecondsSinceEpoch_ > 0;
        }

        int64_t microSecondsSinceEpoch() const
        {
            return microSecondsSinceEpoch_;
        }

        time_t  secondsSinceEpoch() const
        {
            return static_cast<time_t>(microSecondsSinceEpoch_ / kMicroSecondsPerSecond);
        }

    public:
        static Timestamp now();
        static Timestamp invalid()
        {
            return Timestamp();
        }
        static Timestamp fromUnixTime(time_t t)
        {
            return fromUnixTime(t, 0);
        }
        static Timestamp fromUnixTime(time_t t, int microseconds)
        {
            return Timestamp(static_cast<int64_t>(t) * kMicroSecondsPerSecond + microseconds);
        }

        static const int kMicroSecondsPerSecond = 1000 * 1000;

    private:
        int64_t microSecondsSinceEpoch_;
};

inline bool operator< (Timestamp lhs, Timestamp rhs)
{
    return lhs.microSecondsSinceEpoch() < rhs.microSecondsSinceEpoch();
}

inline bool operator== (Timestamp lhs, Timestamp rhs)
{
    return lhs.microSecondsSinceEpoch() == rhs.microSecondsSinceEpoch();
}

inline double timeDifference(Timestamp high, Timestamp low)
{
    int64_t diff = high.microSecondsSinceEpoch() - low.microSecondsSinceEpoch();
    return static_cast<double>(diff) / Timestamp::kMicroSecondsPerSecond;
}

inline Timestamp addTime(Timestamp timestamp, double seconds)
{
    int64_t delta = static_cast<int64_t>(seconds * Timestamp::kMicroSecondsPerSecond);
    return Timestamp(timestamp.microSecondsSinceEpoch() + delta);
}

}
}

#endif 
